Team Chevelle banner
1 - 14 of 14 Posts

·
Premium Member
Joined
·
7,984 Posts
Try this link Brian. click Just put in your rear ratio, trans. final drive ratio, tire size and mph.
 

·
Registered
Joined
·
145 Posts
Discussion Starter · #3 ·
Thanks Scott, but I don't know what the gears are in a 700r4, I quess I asked the question wrong. "RPM for speed in gear" is the chart I need, but I don't know what to put in for transmission gear ratio. I'm hoping someone knows the ratio of each gear in the 700r4. I should ask Chris at CKPerformance he is definately the trans expert here!
Thanks for the calculator site Scott.

Brian
 

·
Premium Member
Joined
·
7,984 Posts
I did a little checking Brian and found out that the 700r4 has a .70 fourth gear. So on that calc. Use .70 as final drive ratio.
The full ratio's are, 1st-3.06, 2nd-1.63, 3rd-1.0, 4th-.70
 

·
Registered
Joined
·
145 Posts
Discussion Starter · #6 ·
So at 75mph with 3.73 gears I'll turn 2350rpm, with 3.55's I'll turn 2237rpm. Not much difference between the two. Scott why would you choose the 3.55 over the 3.73? Thanks again Scott.
Brian
 

·
Premium Member
Joined
·
7,681 Posts
What are you doing with the car? tHE LOWER THE RATIO, THE BETTER CRUISING YOU'LL GET. Damn, I hate the caps lock. If your not into all the acceleration you can get, stick to a little lower ratio.

I'm in the process of going from 3:73 to 3:08, just so I can cruise a little easier. Granted that you're O.D. tranny will help immensely.
 

·
Premium Member
Joined
·
7,984 Posts
The 700 has a 3.06 first gear so you don't need a lot of rear gear to get off the line. I just thought the 3.55's would be a good all around gear.
 

·
Registered
Joined
·
145 Posts
Discussion Starter · #9 ·
Right now all I do is spin tires in first gear, was hoping posi would help some there. When it shifts to second it kind of bogs a bit, maybe the drastic change of gears from first to second in the 700r4, 3.06 to 1.63, anyway was hoping lower rear gears would help. 3.08's now. I quess I'm looking for the best of both worlds, I want to jump off the line fast and cruise 75 down the highway comfortably, you know the deal, with the A/C on and everything.
 

·
Premium Member
Joined
·
7,984 Posts
I know what you mean. I think with the posi and 3.55's you'll be good to go.
Once I'm done with my frame off, I'm going to drop my ratio down from 4.56 to 4.11's so I can actually hit the Highway's. Right now 75 is 4100rpm, with the 4.11's it will be about 3600rpm. 65 will be at 3200rpm which is where my cam comes in and the motor smooths out.
 

·
Registered
Joined
·
18,902 Posts
just remember that when it's time to get the speedo all calibrated, use the rpm in third gear to find your final drive ratio. if you use the 4th gear ratio, your speedo will read 30% slow. or is that 30% fast? well, it will be off 30%..
 

·
Registered
Joined
·
18,902 Posts
say you end up with a final drive ratio that gives you 2800 rpm at 60 in third gear- that would only be 1960 rpm in overdrive.
if you base the speedo calibration on the 1960 rpm at 60 mph- 1.96:1 final drive ratio- then your speedo will be way off. but if you base it on the 2800- or 2.8:1 final drive ratio- then the speedo will be right on.
 
1 - 14 of 14 Posts
Top